Center for Wetlands and Water Resources
Phelps Lab
University of Florida
Gainesville, FL 32611

July 1992

CFW-92-01

Table of Contents

LIST OF FIGURES ..............................

LIST OF TABLES ..............................

INTRODUCTION.... ...........................

Description of the Study Site ...................

Historic Hydrology ...................

Recent Hydrology ....................

Soils . .. . . .. .. . .

Historic Vegetation Patterns ..............

Recent Vegetation Patterns ...............

Hydroperiod .......................

Vegetation Measurements .....................

Estimating Commonness Using the Pielou Method

Estimating Percent Cover ...............

Importance Values ....................

Species Richness ......... ............

Range of Inundation ...................

Vegetation Mapping ...................

RESULTS AND DISCUSSION ......................

Elevations and Water Levels ...................

Hydroperiod .......................

Vegetation Measurements .....................

Importance Values ....................

Species Richness .....................

Range of Inundation ...................

Vegetation Map .....................

SUM M ARY ..................................

LITERATURE CITED ............................

Appendix A ....................................

Appendix B ...................................

Appendix C ....................................

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Appendix D .............

LIST OF FIGURES

Figure 1. Location of Sunnyhill Farm ......................................... 30
Figure 2. Sunnyhill Farm property boundary showing division into agricultural fields, locations of
vegetation transects, and hydrologic monitoring stations. ................. ... 31
Figure 3. Hypothesized historic vegetation communities of Sunnyhill Farm site, and approximate
location of historic channel of the Oklawaha River. ......................... 32
Figure 4. Soil mapping units at Sunnyhill Farm. ................. ................. 33
Figure 5. Water levels at three locations within Sunnyhill Farm for the Period of Record ........ 34
Figure 6. Species frequency, all sampling events combined. .......................... 35
Figure 7. Cumulative species richness as a function of number of quadrats for transects sampled
at Sunnyhill Farm, May 1990. ........................................ 36
Figure 8. Ranges of inundation and mean depths (A) greater than 10 cm for 26 species occurring
at more than three quadrats. ......................................... 37
Figure 9. Ranges of inundation and mean depths (A) less than 0 cm for 10 species occurring on
more than three quadrats. ............................................ 38

LIST OF TABLES

Table 1. Vegetation classification system used at Sunnyhill. ................. ........ 16
Table 2. Percent inundation of sampling plots at Sunnyhill Farm, February 1989 to September
1990 ............ .......................................... 17
Table 3. Importance values of species found on transect #1, all sampling dates. ............. 18
Table 4. Importance values of species found on transect #2, all sampling dates. ............. 19
Table 5. Importance values of species found on transect #3, all sampling dates. ............. 21
Table 6. Importance values of species found on transect #4, all sampling dates. ............. 22
Table 7. Importance values of species found on transect #5, all sampling dates. .............. 23
Table 8. Importance values of species found on transect #6, all sampling dates. ............. 24
Table 9. Range of depths of occurrence and number of occurrences for all species and all sampling
events. ... ..... . . .. . .. .. . .. . .. . ... 25
Table 10. Maximum, minimum, and mean water depth for 20 most common species on all sampling
events. .. ............................. ..................... 27
Table 11. Range of water depths for 20 species having deepest mean depths, all sampling dates. ... 28
Table 12. Species richness on all transects, all sampling dates. ....................... 29

LIST OF FIGURES

Figure 1. Location of Sunnyhill Farm ......................................... 30
Figure 2. Sunnyhill Farm property boundary showing division into agricultural fields, locations of
vegetation transects, and hydrologic monitoring stations. ................. ... 31
Figure 3. Hypothesized historic vegetation communities of Sunnyhill Farm site, and approximate
location of historic channel of the Oklawaha River. ......................... 32
Figure 4. Soil mapping units at Sunnyhill Farm. ................. ................. 33
Figure 5. Water levels at three locations within Sunnyhill Farm for the Period of Record ........ 34
Figure 6. Species frequency, all sampling events combined. .......................... 35
Figure 7. Cumulative species richness as a function of number of quadrats for transects sampled
at Sunnyhill Farm, May 1990. ........................................ 36
Figure 8. Ranges of inundation and mean depths (A) greater than 10 cm for 26 species occurring
at more than three quadrats. ......................................... 37
Figure 9. Ranges of inundation and mean depths (A) less than 0 cm for 10 species occurring on
more than three quadrats. ............................................ 38

LIST OF TABLES

Table 1. Vegetation classification system used at Sunnyhill. ................. ........ 16
Table 2. Percent inundation of sampling plots at Sunnyhill Farm, February 1989 to September
1990 ............ .......................................... 17
Table 3. Importance values of species found on transect #1, all sampling dates. ............. 18
Table 4. Importance values of species found on transect #2, all sampling dates. ............. 19
Table 5. Importance values of species found on transect #3, all sampling dates. ............. 21
Table 6. Importance values of species found on transect #4, all sampling dates. ............. 22
Table 7. Importance values of species found on transect #5, all sampling dates. .............. 23
Table 8. Importance values of species found on transect #6, all sampling dates. ............. 24
Table 9. Range of depths of occurrence and number of occurrences for all species and all sampling
events. ... ..... . . .. . .. .. . .. . .. . ... 25
Table 10. Maximum, minimum, and mean water depth for 20 most common species on all sampling
events. .. ............................. ..................... 27
Table 11. Range of water depths for 20 species having deepest mean depths, all sampling dates. ... 28
Table 12. Species richness on all transects, all sampling dates. ....................... 29

INTRODUCTION

This is a report summarizing analysis of vegetation dynamics on the Sunnyhill Farm, located in southeastern
Marion County, on the western edge of the Ocala National Forest (see Figure 1). The property was purchased by
the St. Johns River Water Management District (the District) for the purposes of restoring wetland ecosystems on
lands that had been converted to agricultural uses around the turn of the century.
The purpose of this vegetation study was to document natural recruitment and successional patterns over
the site and relate environmental variables (soil types, hydrology) with vegetation and succession. The idea was
to broadly characterize vegetation and successional patterns and to determine recruitment over the entire site. As
a result, the study was organized to collect field data at a scale and frequency to determine overall patterns of
change. Soil survey data were used to assist in surmising historic vegetation patterns, while trends in successional
patterns and relationships to depths and periods of inundation will help determine management strategies for
"reclamation" of the wetland communities of the site.

Description of the Study Site

The study site is approximately 1580 hectares (3900 acres), divided into 6 fields separated by a network
of drainage canals and roads (see Figure 2). Fields have been numbered separately to facilitate discussions.

Historic Hydrology
The agricultural fields, which comprise the majority of the Sunnyhill Farm site, were at one time in the
floodplain of the Oklawaha River, and were subject to flood inundation, probably on an annual basis. Initial work
on the channelization of the river and subsequent conversion of the wetlands associated with the old floodplain into
agricultural uses occurred in the 1920s. The canal and levees were substantially reworked and "improved" in the
late 1960s and early 1970s, as part of the Four River Basins Project (D. Walker, District Field Program Manager,
personal communication). Interpreted from 1940 aerial photography where remnants of the old river channel were
still visible, the map in Figure 3 gives an indication of the location of the Oklawaha River channel prior to the
construction of the downstream (north) dam at Moss Bluff and channelization of the river along the western
boundary of the site.

Recent Hydrology
Sunnyhill Farm was extensively ditched and cross ditched for purposes of water control, especially during
summer wet seasons. Several pumps were used at various points within the site for the movement of water, since
the minor topographic relief of the tract precluded gravity flows.
Since the Oklawaha River was channelized, the site has been entirely removed from the effects of its
floodwaters, and receives water inputs from rainfall, and groundwater seepage and overland flow from the
surrounding lands. The drainage area associated with the site is thus substantially reduced from its historic patterns.
A 2-foot-diameter culvert in the canal dike by the southwest corner of the site is the only connection with the canal,
and is an additional source of water available to the site.

Soils
A map of soil types as classified by the Soil Conservation Service (SCS) is given in Figure 4. This map
shows the site to be dominated by the soil series Everglades Muck in the southern areas (fields 1-5) and Iberia Clay
throughout the northern areas (field 6). Both of these soil types are classified by the SCS as hydric soils (Hurt,
1986).
Everglades Muck is a flat, poorly drained soil that is frequently flooded, and has a deep organic layer--this
latter characteristic making it attractive for drainage and conversion to agricultural uses. The native vegetation of
Everglades Muck "consists of thick stands of sawgrass in some areas and willow, loblolly pine, bay, buttonbush,
and maidencane in others" (Aydelott et al. 1975, p. 14).
Iberia Clay is also level, poorly drained, and frequently flooded. In contrast to Everglades Muck, however,
Iberia Clay is dominated by clays of very low permeability, and are thus of less agricultural value. "Natural
vegetation consists of sweetgum, hickory, hornbeam, magnolia, cabbage palm, wild grape, smilax, and poison-ivy"
(Aydelott et al. 1975, p. 15).

Historic Veeetation Patterns
Vegetation patterns of adjacent areas along the river that had not been disturbed are apparent from the. 1940
aerial photography. Interpretation of the photography for these adjacent areas and use of soils as indicators of past
vegetation suggested that the old river channel was dominated by mixed hardwood swamps in the northern portion
of the site and open expanses of marsh in the southern portion. Hypothesized vegetation cover, based on the soils
map of the site and interpretation of the 1940 photography, is shown in Figure 3. The marshes appear to be
dominated by saw grass (Cladium jamaicense), although the quality and scale of photography is such that
confirmation is difficult. Vegetation community types shown in Figure 3 are combinations of classification systems
used by the Florida Department of Transportation (FDOT 1985) and the Center for Wetlands and Water Resources
(Brown and Starnes 1983), using native vegetation given by Aydelott et al. (1975).

Alternately, an 1891 Annual Report and 1912 survey by the U.S. Army Corps of Engineers (R. Fulton,
District Environmental Specialist IV, pers. comm.) suggest that even the northern portions of the site were
historically dominated by sawgrass marsh. The discrepancy between these two sources cannot be easily resolved.
However, based on the high degree of sinuosity exhibited by the old river channel in the northern portion of the
site and familiarity with SCS mapping techniques, the authors lean towards the interpretation given in Figure 3.

Recent Vegetation Patterns
Prior to purchase by the District, Sunnyhill Farm was used as a dairy farm with rotation areas of pasture
and crops given over to silage. Following purchase, water management practices that maintained "dry" conditions
favorable to cattle and crop production were discontinued. As a result, water levels over the site have risen.
Installed water level gages have recorded water levels since early 1989.
While no systematic vegetation surveys were conducted prior to the increases in water levels, the following
vegetation patterns can be surmised from site visits and conversations with individuals familiar with the site prior
to and immediately following purchase. During the time of abandonment and prior to inundation, the old fields in
the southern portions of the site (fields 1-5 in Figure 2) were dominated by a mix of early successional weedy
species that were subsequently killed by rising water levels. Luxuriant growths of sicklepod (Cassia obtusifolia),
day-flower (Commelina difusa) and thick vines of morning glories (Ipomoea spp.) were observed in late 1988.
Many of the old drainage ditches in this same area were "clogged" with floating and emergent aquatic
vegetation, including pennywort (Hydrocotyle ranunculoides), cattails (Typha spp.), water hyacinths (Eichhornia
crassipes), duckweed (Lemna spp.), water ferns (Salvinia rotundifolia), and bog-mats (Wolffiella gladiata). With
increasing water levels, conditions throughout the site are more conducive to wetland and aquatic vegetation.

Plan of Study
Vegetation patterns, recruitment, and successional changes were studied over two growing seasons
beginning with the change in water management in the winter of 1988-1989. Vegetation transects through portions
of the site were established at the end of the first growing season (September 1989), and elevation, water depth,
and vegetation were measured at regular intervals along their entire lengths. Similar transects were established at
the beginning (May 1990) and end (September 1990) of the second growing season. The inset on Figure 2
summarizes the sampling dates for each of the transects shown on the map.
Color infrared aerial photography, which was taken in the fall of 1990, was used in conjunction with the
field data to quantify vegetation patterns over the entire site. Water level data collected by District staff at regular
intervals were related to field data to gain insight into the dynamics of depth and duration of flooding as they relate
to vegetation patterns and successional changes.

METHODS

On September 23, 1989, May 7-9, 1990, and September 23, 1990, vegetation analyses were conducted in
several areas of the old agricultural fields at Sunnyhill Farm. These analyses involved the establishment of transects
which were used to measure relative elevations of the ground surface, water depths, and vegetative cover in 1-m2
plots at regular intervals along the transects.
Since transects were established to characterize vegetation on the site as a whole, permanent transects were
not established; rather, beginning locations were established and transects were extended along a compass bearing.
As a consequence, each sampling quadrat on each of the sampling trips is considered a unique set of data rather than
two or three replicates (depending on number of times sampled) of the same location.

Transect Establishment

The approximate locations of the transects are shown in Figure 2. The intention was to collect data in areas
representative of the varying conditions that existed on the site at the time of measurement. Transects lengths varied
depending on the homogeneity of the area, and on two occasions were ended when impassable conditions prevented
forward progress. Vegetation was measured on a total of 12 transects during 3 sampling trips at 6 different
locations.
Transect #1 (TI) was begun in the southeastern section of the site (field #2), near the water level recorder
that has been used to monitor water depths since February, 1989. The transect was run due west for 470 meters,
stopping at a transecting drainage canal. Transect #2 (T2) was begun in the central portion of the site (field #4),
and run northwest 400 m. These were the only transects measured on all 3 sampling trips.
Transect #3 (T3) was begun along the southwestern edge of the site (field #3), from atop the levee
bordering the Oklawaha River Canal, and run northeastward into the site 100 meters, and east an additional 260
m. This transect was stopped at 360 m at a thick stand of wax myrtles (Myrica cerifera) and blackberry vines
(Rubus spp.). Because of its more upland characteristics, T3 was not sampled on subsequent field trips.
To better characterize field #3, transect #4 (T4) was established on the second field trip, running due north
from the levee, starting approximately 200 meters north of T3. This transect was 200 meters long, and was also
measured on the final sampling trip.
Also on the second sampling trip, a transect (T5) was established to characterize field #5. This transect
was 200 meters in length, was run due east from the western levee, and was also sampled on the final field trip.
Finally, transect #6 (T6) was established on the second sampling trip, in order to characterize the remnant
forest area in field #6. Tree species and underlying herbaceous cover were measured along this 100-meter transect,
just on this single occasion.

Elevations and Water Levels

For each transect, several 100-m fiberglass measuring tapes were laid end to end until the desired length
was attained. Relative elevations along the transects were measured using a survey level and stadia rod on dry land,
and depths of water where the ground was inundated. Elevations were measured at 10-meter intervals, except where
extreme variations in the ground surface warranted smaller intervals. At transition points from dry land to standing
water, both elevation and water depth were measured at two consecutive points, for accurate correlation. From that
point on, water depths alone were measured, and later converted to relative ground-surface elevation.

Long-term Water Levels
Staff gages for monitoring daily changes in water levels were established in each of the major fields by the
District in early 1989. A continuous water level recorder was established in the southeast field around the same
time by CFWWR personnel. Locations of these gages are shown in Figure 2.
From data collected at the staff gages, it was possible to determine the true elevation (feet, mean sea level)
of the ground surface and water levels on the transects on the day field sampling was conducted, making the
assumption that water levels at the gages were representative of the entire fields. Using elevation data along the
transects in conjunction with daily water levels from the staff gages, it was then possible to determine the percent
of time during the period of water level measurements that there was standing water in each of the plots
(hydroperiod), and the extent of that inundation (range and average water depths). These data were then compared
to the parameters determined from the analyses of the vegetation data that were collected. Data from station SE
were used for T1, from station SW for T2-4, and from station NW for T5 and T6 (see Figure 2).

Hydroperiod
Water level data from the staff gages received from the District are for the period 2/13/89-12/31/90 for
NW, SE and SW, and 4/13/89-12/31/90 for DC. Elevations of the water levels for each day of the period of record
were compared to the elevation of each plot in the transects, to determine the number of days that there was
standing water at each plot. Number of days of standing water, divided by total period of record (588 days),
multiplied by 100, produced hydroperiod for each plot as percent of time.

Vegetation Measurements

Vegetation was measured using techniques developed by Pielou (1986), and modified in a recent study by
CFWWR and the U.S. Environmental Protection Agency (Brown and Tighe 1989). At each interval along the
transects (10 or 20 meters, depending on overall length of the transect) a 1-nm sampling frame (quadrat) was laid

out along the tape. Within each quadrat species were identified, and both "commonness" (Pielou) and percent cover
(cover) were estimated.

Estimating Commonness Using the Pielou Method
The Pielou method is a means of comparing the relative commonness or rarity of the vegetation species
at a site. It is a somewhat subjective technique, in which the observer (botanist) denotes species that are seen within
certain time frames. Specifically, all species observed in the first 15 seconds are most common, denoted by a 3
on the field sheet. Those observed in the next 15 seconds (15-30 sec.) are less common, and are denoted by a 2.
Those in the next 30 seconds (30-60 sec.) are uncommon, and denoted by a 1. Those species that are not observed
in the first minute, but which are subsequently found during the cover analysis (see below), are rare, and are
denoted by 0.

Estimating Percent Cover
Cover is an estimation of the areal extent of a particular species. Using grid marks along the edges of the
quadrat as a guide, the botanist estimates the percent of the quadrat that is covered by all vegetative structures of
each species. Because of stratification of species perpendicular to the ground surface, it is possible (and frequently
occurs) to have cover of greater than 100% within a quadrat.

Importance Values
Data from the commonness and cover estimates were used to derive a modified importance value. This
parameter gives an indication of the importance each species plays in the vegetative composition of a transect.

Generally, importance values are based on the average of three terms known as relative frequency, relative
dominance, and relative density (Smith 1980). Because of the types and methods of measurements made in this
study, the importance value was derived from the factors relative frequency, relative cover, and relative
commonness.
Relative frequency. The frequency of a species is the number of quadrats that it appears in along the
transect. The relative frequency of a species is its frequency divided by the sum of the frequencies of all species
on the transect.
Relative cover. A species' cover (dominance) is the average of the covers of that species in all quadrats
along the transect. The relative cover is the cover divided by the sum of all covers of all species on the transect.
Relative commonness. A species' commonness is the average of its commonness values from all quadrats
on a transect. The relative commonness is the species commonness divided by the sum of the commonness of all
species.

Finally, the importance value (IV) for a species is determined by summing the relative frequency, relative
cover, and relative commonness, and dividing by 3. The sum of all IVs on a transect, excepting rounding errors,
is 1.0.

Forested Plots. On transect T6 diameter at breast height (dbh--approximately 1.3 m above ground level)
was measured for all tree species. This obviously included only those species that were at least 1.3 meters tall;
those of less height--considered to be the shrub layer-were not measured, and were thus not included in analyses.
Importance values for species along this transect were based on the traditional measures of relative
frequency, relative density, and relative dominance (Smith, 1980). The transect was 100 meters long by 10 meters
wide. Trees were measured for dbh in each 10 x 10 m block along the transect. There were thus 10 sampling plots
along the transect.
For each species on the transect, the number of plots in which it was found was divided by the total number
of plots (10), to determine frequency. The frequency of each species was then divided by the sum of frequencies
of all species to determine the relative frequency of the species.
The relative density for each species was determined by dividing the number of individual stems of the
particular species by the total number of stems of all species. The dbh values for each individual tree was converted
to basal area, and summed for each species. Total basal area for each species was then divided by total basal area
of all species, to determine the relative dominance of each species. The 3 relative values were then summed for
each species, and divided by 3 to determine the importance value of each species.
Herbaceous species and seedlings of woody species were observed for approximate percent cover in a 1-m2
quadrat located at the beginning of each plot. Relative frequencies and relative covers were determined for each
species, as described above. Since the Pielou method was not applied to these plots, importance values were
determined by adding the relative frequency and relative cover for each species, and dividing by 2.

Species Richness
Species richness refers to the quantity of species per given area. Since there were varying numbers of.plots
along each transect, the absolute numbers of species cannot necessarily be compared between transects. However,
it would not be accurate to simply divide the numbers of species by the number of plots sampled, since cumulative
species occurrence generally increases greatly with initial sample plots and then levels off (Smith 1980). There thus
occurs a point where additional sample plots add no new species to the list of species found. Instead, cumulative
species curves were developed for each transect to determine the number of plots at which species numbers levelled
off. Species occurrence was then standardized between transects, using an equivalent number of quadrats.

Range of Inundation
All vegetation species have certain moisture requirements, and thus varying tolerance to drought and flood
regimes. Some species are also more tolerant to greater depths and frequency of flooding than others.
Based on water depths occurring in the plots measured during the field survey, the range of depths of water
in which each species was found was determined. The water depths of all plots in which an individual species was
found were analyzed, and minimum, maximum, and average water depths for the species were determined.

Vegetation Mavving
A vegetation map was interpreted from false color infrared aerial photography at a scale of 1"=600 feet.
The photography was taken in the fall of 1990. The classification system used was developed for the Sunnyhill
property to reflect its early successional wetland and upland vegetation. The classification scheme is based on
dominant vegetation. In each class there may be more than one plant species present, but the species for which the
class is named is clearly dominant. Table 1 gives the classification scheme. It was developed and numbered so
that classes of vegetation could be easily added as the photo interpretation and ground truthing progressed. In
general, numbers less that 10 were reserved for open water and floating aquatics, numbers from 10 to 19 were
reserved for wetland emergent vegetation, and numbers from 20-29 were reserved for shrubs and drier, successional
vegetation. To speed reproduction of the map and to reduce error in redrafting, the classification scheme was not
renumbered using consecutive numbers.
Production of the vegetation map was accomplished in a three step process. First, vegetation signatures
were interpreted from false color infrared photography by placing a clear acetate overlay on each frame of the
photography and outlining the different vegetation associations. Outlined vegetation associations were numbered
according to the classification scheme given in Table 1. Second, the map was groundtruthed in the field during
early September, 1991. And third, once groundtruthing was complete, the individual acetate overlays were
combined using a controlled base map provided by the District and redrawn on a single sheet at a scale of 1" = 600
feet.

RESULTS AND DISCUSSION

Elevations and Water Levels

Elevation profiles for the 12 transects measured on the three sampling trips are shown on the figures given
in Appendix A. The profiles are scaled alike for comparison of transect lengths and ground surface roughness.
Water depths on the day the measurements were made are also shown on these profiles. Ground surface roughness
varies from one sampling date to the next on the same transect because transect locations were relative.
Average monthly values of water levels during the period of record for the four staff gages are shown in
Figure 5. These data are given in feet since they were recorded as feet msl by District staff. The spikes in the data
for the SW/SE drainage canal (DC) in October 1989 and January-February 1990 were probably due to pumping
activities undertaken by the District at that time (Fulton, District Environmental Specialist IV, pers. comm.). Water
from both the southeast and southwest fields was pumped into the drainage canal, which is located on the north side
of the levee separating fields 4 and 5 (Figure 2). This water failed to drain quickly, causing short-term flooding
in the drainage canal.
Water levels varied about 1.7 feet (51.2 feet msl to 52.9 feet msl) throughout the site during the period
of record with the exception of two events in the drainage canal where water levels were approximately 53.8 feet
msl. For the most part, water levels at the NW and SW gages were identical, but departed during August -
December of 1990. Water levels at the SE gage averaged about 0.7 feet lower than the NW and SW gages during
the period of record.

Hvdroperiod
Hydroperiods (as percent inundation) for each plot on transects 1, 2, 4, and 5, for the period of record,
are listed in Table 2. These were the four transects which were sampled on the final (9/90) field trip, and
corresponded to the marsh areas that were analyzed. Transect 3 (T3) was composed of mostly upland shrub species,
and most of the plots were at elevations above any standing water during the period of record (POR). T6 was
completely dry during the POR.
Transect T1 was nearly 100% inundated for the entire POR. Four plots were dry at some time during the
POR, and only two of these for more than 2 % of the time. T2 was completely inundated in the marsh portions of
its length (plots 1-11, Table 2) for the entire POR. The shrub region (approximately 230-285 m) was primarily dry,
although standing water did occur here for a portion of the study period. Transects 4 and 5 were also inundated
for essentially the entire POR. A 40-m stretch of T4 was dry less than 3 % of the study period, while only 1 plot
(#14) was ever dry on T5 (Table 2).

10

Vegetation Measurements

Importance Values
Commonness and cover values for all species on each transect are listed in Appendix B-D. Importance
values for species on each transect, for each sampling period, are listed in Tables 3-8. The species found on all
sampling trips are listed in each table (when applicable), so that changes in species' importance and composition
at each transect in the site can be compared.
By far the dominant species on the marsh transects (T1, T2, T4 and T5) were duckweed (Lemna spp.),
water hyacinths (Eichhornia crassipes), bog-mats (Wolffiella gladiata), floating pennywort (Hydrocotyle
ranunculoides), and water ferns (Salvinia rotundifolia), all of which are free-floating, herbaceous wetland species.
Giant duckweed (Spirodela spp.) was also important on T2 and T5 while frog's bit (Limnobium spongia) was the
dominant species on T5. In various combinations, these seven species accounted for greater than 45% of the
importance on all sampling trips on all marsh transects, and generally greater than 60% (see Tables 3, 4, 6, and
7).
Transect 3, on the other hand, was mostly dry, and was dominated by species indicative of early succession
on drier soils. Most common was sicklepod (Cassia obtusifolia), with an importance value of 0.34. A substantial
amount of day-flower (Commelina difusa) was also present on this transect (IV=0.16). Only 1 quadrat on this
transect was in deep water (plot #19) and was the only plot in which marsh species were dominant (see Appendix
B, Table B3a).
As shown in Table 8, the primary tree species in the remnant floodplain was red maple (Acer rubrum), with
an IV of 0.58. Wax myrtle (Myrica cerifera) was important in the understory (IV=0.20). The ground cover was
dominated by the wetland indicators royal fern (Osmunda regalis), cinnamon fern (0. cinnamomea), and lizard's-tail
(Saururus cernuus), with importance values of 0.37, 0.21, and 0.16, respectively.
Species data were summarized for the three field sampling events and are given in Figure 6 and Tables 9,
10 and 11. Table 9 lists all species in alphabetical order, giving the number of quadrats in which they were found,
and their range of water levels. Table 10 lists the 20 most common species and their range of water levels, and
Table 11 list the 20 species found in deepest mean water depths.
The frequency distribution in Figure 6 and tabular data in Table 10 shows that of the 63 species found on
all transects, eight species dominated in a number of occurrences (Eichhornia crassipes, Salvinia rotundifolia, Lemna
spp., Hydrocotyle ranunculoides, Wolffiella gladiata, Spirodela spp., Typha domingensis, andLimnobium spongia).
Of these 8 species, 5 are floating aquatic plants (Eichhornia crassipes, Salvinia rotundifolia, Lemna spp., Wolffiella
gladiata, Spirodela spp.), one is a floating aquatic during its juvenile phase (Limnobium spongia), one is often a
floating plant in dense mats, but can be rooted (Hydrocotyle ranunculoides), and one is a rooted perennial herb
(Typha domingensis).

The most common rooted, aquatic plant species (other than Typha) were Juncus effusus, Pontederia
cordata, Panicum hemitomon, Alternanthera philoxeroides, and Ludwigia spp. The most common non- aquatic
species were Eclipta alba and Eupatorium capillifolium.

Species Richness
Table 12 summarizes the change in species richness for each of the transects. A general trend of increasing
numbers of species at each transect for successive sampling trips can be seen.
The cumulative number of species found on transects sampled in May 1990 versus successive plot number
for the transects in Figure 7. First, on plots 1 through 20 on each transect, it can be seen that somewhere between
5 and 10 plots suffice to account for nearly all of the species found on each transect. Transects 1 and 2, which go
beyond 20 plots, each next encountered an entirely different community from the deep marsh measured in the earlier
plots. Transect 1 ended at a berm along a drainage canal, and thus was drier with new species for the last two plots
measured (see Figure A3 [top] and Table Cla). Transect 2 crossed a substantial stretch of dry land and more than
tripled the numbers of species encountered (see Figures 7 and A3 [bottom], and Table C2a). But even with this
new community and additional species, the cumulative total leveled off again after about 10 plots (Figure 7).
Based on this finding, species data were reevaluated using only species occurring in the first 10 plots of
each transect. For transect 2, the herbaceous and upland portions were divided into separate components. Revised
data are presented in the lower portion of Table 12. The primary finding of these results is that a greater number
of species were found in drier habitats. The marshes, particularly in the SE and SW fields (T1 and T2,
respectively), had a much less diverse mix of species.

Range of Inundation
Table 9 gives upper, lower, and mean water depths for each species found on all transects, summarized
for all field sampling events. These data are the recorded water depths on the day of field measurements. Positive
numbers indicate standing water above the ground surface, and negative numbers indicate groundwater below the
soil surface. Table 9 also lists the number of plots in which each species was found. The range of water depths
for the 20 species with deepest mean depths is given in Table 11 (species with only one occurrence are omitted from
the table). Figure 8 summarizes variation between maximum and minimum water levels for the 26 "wetland
species" having quadrat occurrences greater than 3, and Figure 9 gives the same data for the 10 "upland species"
occurring in greater than 3 quadrats'.

Definition of "wetland" and "upland" species follows the listed species under Florida Administrative
Code Rule 17-4.022. Any exceptions to this nomenclature are noted in the text.

Of the most common "wetland species", the floating aquatics: Eichhornia crassipes, Salvinia rotundifolia,
and Lemna spp. were found in areas with deepest maximum water levels and had the widest variation in water
depths. The rooted aquatic (and sometime floating mat), Hydrocotyle ranunculoides was also found in deep water
and had the widest variation between maximum and minimum water levels, although mean water level was shallower
than the floating aquatics. Wolfiella gladiata had the deepest mean water depths, but was not found in water
depths greater than 88 cm.
An unidentified Polygonum spp. was found in the deepest mean water depths (varying from 163 cm to 22
cm). In general the floating aquatics were found at mean water depths greater than 44 cm and the rooted emergent
species at mean water depths less than 30 cm. The exceptions were Alternanthera philoxeroides (37 cm), Cyperus
strigosus (35 cm), and Panicum hemitomon (31.4 cm). Typha domingensis was found at a mean water depth of 28.6
cm (70 cm to -15 cm).
Relatively common species with ranges of water depth of less than 70 centimeters included: Azolla
caroliniana (70 cm to 1 cm), Pontederia cordata (71 cm to 1 cm), Panicum hemitomon (70 cm to 0 cm),
Alternanthera philoxeroides (70 cm to 3 cm), an unidentified Ludwigia spp (41 cm to 15 cm), and Commelina
diffusa (37 cm to 5 cm). Three species (Commelina diffusa, Cyperus strigosus and Ipomoea trifida) are not listed
as "wetland species" in Chapter 17-4 FAC.
The 10 species in Figure 9 have mean water depths of 0 cm to -30 cm. Of these species 8 are upland and
2 are considered wetland species (Cyperus haspan and Juncus marginatus). Eclipta alba, Cassia obtusifolia,
Cyperus haspan and Eupatorium capillifolium were each found in quadrats that were inundated, but whose mean
depths of inundation were less than 0. The remaining species were all found in quadrats that ranged in water depth
from -5 cm to -36 cm.

Vegetation Map
A vegetation map of the Sunnyhill Farm is included as a map folio. The old patterns of drainage canals
and levees, exhibited by differences in vegetation were still quite obvious throughout the site. Ditching was most
evident in fields 1, 2, and 3, and the northwest portion of field 4. Remnants of the original river channel-were
evident in field 5 and the upper portion of field 4.
Field 1 appeared to be dominated by Typha spp. with large areas of Hydrocotyle ranunculoides and smaller
patches of open water. Field 2 had large areas of the floating aquatic, Eichhornia crassipes and significant areas
of open water. The extreme northern portion of field 2 was drier, and supported areas of the shrubs Ludwigia spp.,
Myrica cerifera and Salix spp. Field 3 was most difficult to classify since it had a larger diversity of vegetation,
presumably the result of drier conditions. Areas of Typha spp. were mixed with early successional shrub and
herbaceous species. There were fairly large areas of open water and Lemna spp. in the southern and central
portions of field 4. The northwest portion of field 4 was drier, supporting the shrubs Ludwigia spp., Myrica

13

cerifera and Salix spp. Field 5 had significant areas of open water, Lemna spp., and Hydrocotyle ranunculoides
along both sides of the remnant river channel. Drier areas of shrubs and herbaceous species dominated the extreme
eastern and western edges of the field. The driest field was field 6, the southern portion of which was dominated
by forested areas and stands of robust concentrations of Myrica cerifera.

SUMMARY

During the two growing seasons (1989-1990) that were the subject of these field samplings since the change
in water regimes, some general trends in successional patterns might be deduced:
The soil seed bank seems to be depauperate of species characteristic of the communities originally
occupying the site. It is possible that this is simply a result of a lack of conditions conducive to
the germination of such species. However, when one considers the amount of time that has
elapsed since conversion to agricultural uses and the effects of such uses on the soil, this result
is not surprising.
A significant component of wetland herbaceous species have colonized the site in areas where water
depths favor their establishment.
In the two growing seasons observed, there was little change in species composition as measured at the
transects. All of the marsh areas were dominated by floating and rooted aquatic species, with the
same five or six species of greatest importance values throughout the site. There was a slight
trend in increasing species richness over al sampling trips.
Based on observations of successional patterns of the site, it is unlikely that the original (hypothesized)
vegetation characteristic of the site will recolonize. If the original vegetation was saw grass
(Cladium jamaicense), the changes in water quality, quantity and flow regimes, and the
disturbance to soils may not be conducive to its re-establishment. In addition, saw grass is known
to be very difficult to germinate or transplant.
Species richness tended to be greatest in those areas of lowest overall water depths. Transect 2 had
highest overall richness because it had both submerged and "exposed" areas. In submerged areas,
highest species richness seemed to occur on plots having inundation depths of less than 60
centimeters.
Sites with mean water depths greater than 40 cm were dominated in large part by floating aquatics and
rooted floating aquatics, and sites with mean water depths from 10 cm to 39 cm appeared to be
favored by emergent vegetation.
The mean depth for Typha spp. was 28.6 cm. It was not found in areas with inundation depths greater
than 70 cm., but was found in "dry" areas where water depths were as much as 15 cm below the
soil surface.

Brown, M.T. and R.E. Tighe. 1989. A Florida pilot study for the evaluation of created and restored wetlands.
Report to the U.S. Environmental Protection Agency. Wetland and Water Resources Research Center,
University of Florida, Gainesville. 50 p. + Appendix.